Squashed 'src/ipc/libmultiprocess/' content from commit 35944ffd23fa

git-subtree-dir: src/ipc/libmultiprocess
git-subtree-split: 35944ffd23fa26652b82210351d50e896ce16c8f

include/mp/type-exception.h

@@ -0,0 +1,22 @@
+// Copyright (c) 2025 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef MP_PROXY_TYPE_EXCEPTION_H
+#define MP_PROXY_TYPE_EXCEPTION_H
+
+#include <mp/util.h>
+
+namespace mp {
+template <typename Output>
+void CustomBuildField(TypeList<std::exception>,
+    Priority<1>,
+    InvokeContext& invoke_context,
+    const std::exception& value,
+    Output&& output)
+{
+    BuildField(TypeList<std::string>(), invoke_context, output, std::string(value.what()));
+}
+} // namespace mp
+
+#endif // MP_PROXY_TYPE_EXCEPTION_H